1.Transmission towers with voltage levels of 110kV and above
In this voltage range, most lines consist of 5 conductors. The top two conductors are called shielded wires, also known as lightning protection wires. The main function of these two wires is to prevent the conductor from being directly struck by lightning.
The lower three conductors are phase A, B, and C conductors, commonly referred to as three-phase power. The arrangement of these three-phase conductors can vary depending on the tower type. In a horizontal arrangement, the three phase conductors are in the same horizontal plane. For single circuit lines, there is also a horizontal arrangement in the shape of the letter “H”. For double-circuit or multi-circuit lines, vertical arrangement is usually adopted. It is worth noting that a few 110kV lines have only one shielded wire, resulting in 4 conductors: 1 shielded wire and 3 phase conductors.
2.35kV-66kV voltage level transmission tower
Most overhead lines in this range consist of 4 conductors, of which the top one is still shielded and the lower three are phase conductors.
3.10kV-20kV voltage level transmission tower
Most overhead lines in this range consist of 3 conductors, all phase conductors, no shielding. This refers specifically to single circuit transmission lines. At present, 10kV lines in many places are multi-circuit transmission lines. For example, a double-circuit line consists of 6 conductors, and a four-circuit line consists of 12 conductors.
4.Low-voltage overhead line transmission tower (220V, 380V)
If you see an overhead line with only two conductors on a low concrete pole and a short distance between them, this is usually a 220V line. These lines are rare in urban areas but may still be visible in rural greenhouse areas. The two conductors consist of a phase conductor and a neutral conductor, namely the live and neutral conductors. Another configuration is a 4-conductor setup, which is a 380V line. This includes 3 live wires and 1 neutral wire.
Post time: Aug-01-2024
